This invention relates to microfilm information systems and more particularly to an improved microfilm information system utilizing an improved microfilm card and microfilm reader.
In the past there have been various types of information storage arrangements in which images have been reduced in size and recorded on microfilm. In one common application, the images are arranged in vertical columns and horizontal rows on a microfiche card, commonly referred to as a fiche. These fiche are normally four inches by six inches and have a title block area along the top of the fiche. In a typical microfilm reading apparatus, the fiche is held by means of a carriage which is movable in two horizontal directions in the focal plane of a projection lens. Each image is capable of being projected to a convenient viewing surface or screen. The fiche is usually inserted and removed manually from the carriage and multiple image frames must normally be searched until the desired subject matter is found. Some microfilm readers utilize an index pointer attached to the carriage and an index grid on the microfilm reader to aid the user in positioning the carriage so that a preselected frame can be quickly placed in the projection path. However, such index pointers are frequently not accurately positioned with respect to the microfilm or the index grid. This results in an image being projected on the viewing screen which does not correspond to the location on the index grid indicated by the index pointer. Due to these inaccuracties they are therefore infrequently used.
While microfilm storage arrangements of the prior art have reduced the storage volume requirements for large volumes of information, they do not fully satisfy the need for rapid retrieval of the information stored on microfilm. Generally, the information is stored on the microfilm by recording a large number of documents simultaneously, or recording the documents in the order in which they are received from an information source. The information is then retrieved from the microfilm by spot scanning the images or by scanning the images in the sequence of recording until the desired information is located and displayed. Obviously, this retrieval technique is undesireable as it requires the operator to scan through large bodies of stored information before the desired information is located. In the case of microfilm cards or fiche, the access time in locating a desired image is substantial as the operator must scan the fiche in both horizontal directions. The use of an index pointer used in association with a location grid does not substantially reduce the searching time as the pointer and grid are usually not in registration with the fiche. The need therefore exists for a means to rapidly retrieve information stored on microfiche. This is particularly true in the case of large amounts of information stored on numerous microfiche.
The device in U.S. Pat. No. 3,797,925 illustrates a microfiche reader having an indicating grid. A cursor indicates the frame of the fiche card which is in the projection position. However, there is not any positive registration between the fiche card and the indicating grid which guarantees the indicating grid is in registration with the fiche or image projected. The grid is fixed and the movement of the cursor is dependent on movement of the fiche carriage which gives a visual indication of location on the grid. There is not any fiche positioning device to accurately position the fiche on the fiche carriage to guarantee the fiche is in its proper position each time it is to be read. Furthermore, there is not any positive registration between the image and the grid.
In U.S. Pat. No. 3,822,090, similar problems are encountered. The grid is not connected to nor does it necessarily relate to the image projected. The index is not integral with the images on the fiche. Furthermore, there is no accurate registration between images and the fiche index, which is further complicated by the use of a pantograph.
In U.S. Pat. No. 3,885,567, the same or similar shortcomings are experienced as in the two previously cited references. There is again no registration between the grid index and the images as only an illuminating light is projected onto the grid to indicate the image location being projected.
A film card having reference frames which can be used for positioning of a raster pattern on the remaining frames is illustrated in U.S. Pat. No. 4,225,217. The reference frame only includes a marker image. However, this device does not use an index grid in conjunction and affixed to the microfilm images. Thus, the operator does not have a corresponding image for which he is searching by merely viewing the index grid.
U.S. Pat. No. 3,868,179, illustrates a microform positioning device having a plate member of microfilm carriage which has a series of aligned projections which cooperate with recesses which are part of the reader. This enables the microfilm carriage to be incremented in discreet incremental movements which are designed to correspond with the rows of images on the microfilm. However, the microfiche does not integrate corresponding operator viewable index images with the microfilm images.
One other microform information storage unit is disclosed in related U.S. Pat. Nos. 3,980,401 and 3,980,402. The microfilm information storage unit has an information storage area and an index area, both affixed to a sheet by means of an adhesive. However, the index images are not directly operator viewable and do not correspond to an expanded image index. Furthermore, there is not any means to align or position the microfilm storage unit into the reader such that it is positioned in the reader in the same exact location each time.
The inventive device described herein has a microfilm card which has both an image area and an index area which is adjacent to the image area. The index area is precisely and accurately positioned with respect to the image area. There are operator viewable indexes on the index area which allow the operator to easily and quickly locate the general subject which is being searched for. By properly positioning the index in the microfilm reader, an expanded index is projected from the image area onto the microfilm reader's screen. The expanded index gives the operator the exact location in the row of micro images at which the desired information can be found. The microfilm card has tabs or projections extending from the side of the card which interface with posts on the microfilm reader such that the card is accurately and positively positioned in the microfilm reader each time it is to be viewed.
Thus, it is an object of this invention to provide a new and improved microfilm card. It is a further object to provide a microfilm card which is adapted to be used with a microfilm reading device wherein the card has tabs or projections which interface with the microfilm reader to accurately position the card in the reader. A related object is to provide a microfilm card which uses the projections on the card to hang the card from a rack storage device for convenient filing and storage. The projections can further be used to place filing information thereon.
Another object is to provide an information retrieval system wherein a microfilm card has an operator viewable index which can be used to quickly locate the general subject matter being searched and project on the microfilm reader's screen an expanded index directed to the specific information sought.
Other objects and advantages will become apparent on reading the following brief description of the drawings and description of the preferred embodiment.